Leaf spot disease control using Neem oil:

Leaf
spot is a fungal disease caused by the
fungus such as Pyrenophora tritici-repentis,
Cercospora zein, Cercospora zeae-maydis,
Colletotrichum graminicola, Puccinia sorghi,
etc. in various food and ornamental crops
as well. The spot in the leaves of the plant
is identified in brown, black and yellow
pigments. It spreads to the entire foliage
slowly making the plant look decomposed
and on later stage the leaves get withered.

Transmission of the disease to the adjacent
plants may be due to wind factor. These
bacterial or fungal spots are observed to
be active during warm-humid environment,
thus spreading is more likely to occur during
the prevalence of such conditions. Mostly
plants fall prey to this disease and rarely
trees. Aesthetic view of flora is one of
the facts that get disturbed by the disease.
Some other symptoms include dark concentric
rings around the spots which on later stage
combine all other spots into a single large
blotch that remains as a stain of the leaves.
Anthracnose is a type of leaf spot disease
causing such intense stains over the leaves
of the sycamore trees. Size and color of
the spots depend upon the plant species
and the fungus involved in the attack. Identification
of the spots is done prior before the treatment
of spots.

Control of disease can be done by some productive
measures like providing ample space between
the plants, sprinkling of water at the lower
level instead of spraying over the leaves,
removal of infested parts of the plant,
spraying of effective organic fungicides
over the infected plants.

Firstly, leaving ample space in between
the plant rows can make sure the disease
not spread to the neighbor plants from the
infected one. The fungus responsible for
the cause of disease is found to spread
by irrigation water that is sprinkled over
the plants and consequently, sprinkling
at the lower level can avoid it. Infested
leaves should be removed for the further
extent of infection.

Organic fungicides like Neem
oil can serve as an effective treatment
of the fungus spots as neem is well known
for it characteristic fungicidal property.
Azadirachtin content of neem oil can eradicate
the fungus present on leaves and can also
evade them from the future spread to the
susceptible plants. The practice of spraying
should be done once in 10 days for efficient
manage of spots. EPA
registered Neem oil shows the positive effect
and it is diluted with water before use.